Nike Dri-FIT ADV technology combines moisture-wicking fabric with advanced engineering and features to help you stay dry and comfortable. Woven fabric stretches for a comfortable, personalized fit. Perforations on the side panels increase airflow. Sweatband is soft and absorbent. Incredibly stretchy and very breathable, the Nike Dri-FIT ADV Classic99 Hat is built to keep you cool and comfortable so you can play at your best, round after round.